关于玉米粒重的研究

玉米百粒重一般多少克，玉米百粒重和容重的区别玉米百粒重一般为26-28克左右，若品种较优良、种植水平较高，则一般可以超过30克。

若想提高粒重，可根据当地的常年温度条件来确定播种期，以满足玉米对积温的需求，使籽粒处于适宜的灌浆温度范围内，同时可在开花期、乳熟期、蜡熟期分别浇水1次，出现玉米螟、蚜虫等害虫后及时做好防治工作。

一、玉米百粒重一般多少克1、百粒重的具体重量玉米百粒重通常为26-28克左右，在品种特性较优良、种植水平较高的条件下，百粒重可达到30克以上。

2、提高粒重的方法（1）适时早播玉米从授粉到籽粒成熟需要一定的积温，若积温不足，则粒重会下降，因此可根据当地的常年温度条件来确定播种期，这样既能满足玉米对积温的需求，又能让籽粒处于适宜的灌浆温度范围内。

（2）防止干旱玉米需要吸收充足的水分才能顺利灌浆，若在开花期、乳熟期、蜡熟期分别浇水1次，则千粒重一般为321.5克左右，若仅在开花期、乳熟期分别浇水1次，则千粒重多为269.5克左右。

（3）防治虫害①玉米螟会危害茎部、穗部，破坏营养运输。

②蚜虫会吸取植株体内的营养，影响籽粒灌浆，导致粒重下降。

③发生此类害虫后及时防治，可在一定程度上增加粒重。

二、玉米百粒重和容重的区别1、区别（1）百粒重：是指100粒种子的重量，表示单位为“克”，它是体现种子大小、充实程度的一项指标。

（2）容重：是指1升玉米在标准的容重器实验下的重量（克），它能够反应玉米籽粒的饱满程度，但会受到水分、杂质的影响。

玉米容重是定等的依据（代替过去的纯粮率），容重越大，则表示质量越高，受到虫蛀、空壳、瘪瘦的玉米粒越少。

2、容重标准（1）一等玉米容重≥720克/升，不完善粒含量≤4.0%，霉变粒含量≤2.0%，杂质含量≤1.0%，水分含量≤14.0%，色泽和气味正常。

（2）二等玉米容重为>720克/升（或≥690克/升），不完善粒含量≤6.0%，霉变粒含量≤2.0%，杂质含量≤1.0%，水分含量≤14.0%，色泽和气味正常。

中早熟玉米产量与其相关性状的研究摘要：本试验选用20个中早熟玉米杂交种为供试材料，采用随机区组设计。

经过对穗长、株高、出籽率、千粒重等5个农艺性状进行相关分析结果表明，对产量影响较大的因素是穗长（p0.4=0.7912**，ｒ=0.8089**）和千粒重（p0.3=0.6215**，ｒ=0.5902**），相关系数达极显著水平，其次是出籽率，株高，穗位高。

指出在吉林省中早熟玉米育种中，提高穗长和千粒重，适当增加出籽率并兼顾其他农艺性状是提高玉米产量的有效途径。

关键词：玉米杂交种；农艺性状；相关分析；育种中图分类号：s513文献标识码：ａ为本文通讯作者玉米的产量是一个受多基因控制的数量性状，是多个性状共同作用的结果，各农艺性状之间也存在着不同程度的相关性［1］。

因此对一个性状的选择势必影响到另一性状的遗传效果，多年来国内外育种者一直在深入研究。

在实际育种中，对性状选择的应该有侧重点，这样才能快速选出生产中急需品种。

目前吉林省大部分地区玉米都种植中到中晚熟品种，为了追求高产有部分中早熟玉米的地区甚至越区种植，不仅达不到高产的目的，反而减产。

因此有些单位忽略了早熟品种的研究，为此，有必要加强中早熟玉米性状和产量方面的探讨。

吉林省东部山区和西部部分地区的玉米生产属于春播中早熟区，无霜期短、降水较少、土壤瘠薄的生态条件使玉米产量和效益很不理想。

选育高产、抗病、优质的中早熟玉米新品种，成为吉林省东部和西部地区的一个迫切任务。

为此，本研究对玉米各主要农艺性状进行了相关和通径分析，找出对中早熟玉米产量贡献较大的性状，仅为吉林省中早熟玉米育种提供参考。

１材料与方法1.1试验材料选用本试验选用30个玉米杂交种为研究材料，品种有：吉单27、吉单18、吉单23、吉单431、a5051、a2365、a4589、a2568、a4456等。

1.2试验设计与分析方法试验地点设在吉林省舒兰市农科院试验基地，试验采用随机区组排列，3次重复，4行区，行长5m。

玉米百粒重与主要籽粒性状的相关分析王国宏;董润楠;孙成韬;李中强;周存立【摘要】[目的]通过配合力测定和相关分析研究玉米百粒重遗传和亲本选择.[方法]以5个自交系为父本、8个自交系为母本,按NCⅡ设计所组配的40个杂交组合为材料,进行了穗部性状的配合力测定和相关分析.[结果]百粒重的一般配合力方差明显大于特殊配合力的方差,分别为65.92％、34.08％,表明该性状的遗传变异,基因的加性效应起着主导作用.13份自交系百粒重GCA效应分析中,PH6WC、中106表现较好.影响百粒重的主要因素是粒厚、穗粗和出籽率,它们的相关系数达到极显著水平,分别为0.39、0.36、-0.39.[结论]百粒重遗传以加性效应为主,同时发挥一般配合力和特殊配合力效应.【期刊名称】《园艺与种苗》【年(卷),期】2015(000)012【总页数】4页(P48-50,59)【关键词】玉米;百粒重;配合力;相关分析【作者】王国宏;董润楠;孙成韬;李中强;周存立【作者单位】辽宁省农业科学院玉米研究所,辽宁沈阳110161;辽宁省农业科学院玉米研究所,辽宁沈阳110161;辽宁省农业科学院玉米研究所,辽宁沈阳110161;辽宁省农业科学院玉米研究所,辽宁沈阳110161;辽宁省农业科学院玉米研究所,辽宁沈阳110161【正文语种】中文【中图分类】S513百粒重是产量重要构成因素之一，如何提高玉米百粒重是玉米遗传育种的重要目标。

百粒重受多种因素影响，是一个多基因控制的数量性状，而且不同学者［1-8］研究结果有较大差异，主要由各个试验所用的材料、鉴定环境、统计方法和群体大小等不相同所致。

近年来，国外玉米种质大量进入中国并且迅速占领市场，如何利用好这些种质已成为每个玉米育种者必须考虑的问题。

笔者以郑单958、辽单565、良玉66、丹玉39、先玉335、迪卡516等8个优良杂交种的亲本自交系组配的杂交种为材料进行百粒重配合力等相关研究和评价，为重粒型玉米种质的创新和利用提供参考。

玉米千粒重一般多少决定玉米粒重的关键
期
玉米的千粒重大约是260－280克，品种特性优良、种植水平高的千粒重可超300克。

玉米千粒重一般多少取决于籽粒体积（即库容）的大小、灌浆速度的快慢及灌浆时间的长短。

农业生产中，玉米受精以后，籽粒体积增长很快。

夏播玉米授粉后14天左右，幼粒体积已达到籽粒最大体积的50%左右；授粉26天以后，体积增长缓慢；至授粉后37天前后，即乳熟后期，籽粒体积已达最大值。

成熟时，因失水，籽粒略有缩小。

因此，从授粉开始20天左右，是决定籽粒体积大小的关键时期，也是促粒大的关键时期。

叶片的光合产物和贮存在茎鞘以及根吸收的营养物质输送到籽
粒的过程叫灌浆。

授粉后头15天左右为籽粒形成期，灌浆速度很慢，这时的粒重仅占成熟时粒重的5%左右。

此后籽粒进入乳熟期，灌浆速度快速增加，至授粉后25天左右，
达到灌浆高峰期，以后缓慢下降。

乳熟期持续20天左右，籽粒积累于物重达成熟时粒重的70%一80%。

因此，这一阶段是决定粒重的关键时期，也是生产上提高粒重的关键时期。

授粉后35天左右，籽粒进入蜡熟期，灌浆速度继续下降，至籽粒完全成熟时，灌浆才会停止。

因此，玉米要在熟透后才能收获。

收早了，粒重轻，产量低。

灌浆时间的长短决定于品种特性和授粉后土壤及气候条件。

早熟品种的灌浆期一般为30多天，晚熟品种的灌浆期可长达50天以上。

授粉后，若土壤水分和养分不足或气温高，则灌浆期变短，粒重低；土壤水分适宜，养分充足，气温较低，则灌浆期长，籽粒饱满，粒重高。

山东农业大学硕士专业学位论文一、引言玉米原产于南美洲，大约在十六世纪中期，中国开始引进玉米，十八世纪又传到印度。

到目前为止，世界各大洲均有玉米种植，是当今世界重要的粮食作物之一，也是集粮、饲、经“三元一体”的优势作物。

我国是一个农业大国，是世界第二大玉米生产国。

玉米在粮食生产中的作用举足轻重，在国民经济中占有重要地位。

自新中国成立的６０多年来，玉米在解决温饱问题、保障粮食和饲料安全、发展国民经济以及缓解能源危机等方面发挥了重要作用。

近年来，随着我国现代农业的快速发展，以及人民生活水平的改善和工业加工能力的不断提高，我国玉米消费量迅速增加，玉米消费结构发生了根本性变化，即由解决温饱的主要粮食作物，发展成为禽畜饲料、工业原料、餐桌副食、能源作物四位一体的多样化格局，特别是近年来再生能源（汽油醇）与精深加工（化工醇）领域赋予了玉米新的内涵，工业加工比例急速增长，多元需求使玉米成为２１世纪举足轻重的战略资源。

近５０年来，我国玉米育种取得了举世瞩目的成就。

玉米品种完成了６次更新换代，并且使优良品种在粮食增产中的贡献率达到了３０％以上ｎ１。

我国玉米优良品种的广泛使用，加上良好的栽培技术，是我国近年来玉米产量稳步提高的关键因素，为保障粮食安全和缓解能源危机做出了巨大的贡献。

玉米是我国重要的粮食和饲料作物。

据测算，２０３０年我国人口将达到１６亿，如果按玉米占粮食份额的四分之一计算，到２０３０年我国玉米的总产应达到１．６亿一１．７５亿吨。

在玉米播种面积不变的情况下，要求玉米单产在１９９８年３５１公斤／亩的基础上，年均增长５公斤庙才能基本满足对玉米的需求乜１。

因此，提高玉米产量对我国农业发展，乃至国民经济的稳定增长十分重要。

１．１玉米种质资源研究与利用现状１．１．１种质资源的概念作物种质资源（ＧｅｒｍｐｌａｍＲｅｓｏｕｒｃｅｓ）Ｙ．．被称为物遗传资源（ＧｅｎｅｔｉｃＲｅｓｏｕｒｃｅｓ），指亲代传递给子代的遗传物质，是控制生物本身遗传和变异的内在因子ｎ１。

不同熟期春玉米籽粒乳线比例与含水率、粒重及激素的关系周颖;顾万荣;张立国;李晶;刘晓双;左师宇;曹鑫波;孙继;魏湜【摘要】[Objective] A field experiment was conducted to illustrate the relationship of milk hne percentage with water content,grain weight and hormone of spring maize to provide a scientific and experimental information for the spring maize maturity selection of different accumulated temperature zone in Heilongjiang province.[Method]‘ Xianyu335’ and ‘ Xinxin2’ (late maturity varieties),‘ Suiyu’ and‘ Jidan27 ’ (mid-late maturity varieties) which had different maturities were used as experiment materials,and their milk line percentage,water content,grain weight and hormones were determined.[Result]Compared with late maturity varieties,mid-late maturity varieties could safety ripen,grain milk line formed faster,water content declined more quickly,and the transportation and accumulation of starch were more quickly.At 55 days after anthesis,the milk line percentage of mid-late maturity varieties was 29.37 ％-35.20 ％ bigger than that of late maturity varieties,and water content was 18.52 ％-19.63 ％ lower than that of late maturity varieties.Changes of hormones were similar in varieties but differed in diferent maturity varieties,compared with late maturity varieties,IAA,GA,CTK contents were lower in mid-late maturity varieties,and grains were more mature.ABA content of mid-late maturity varieties was higher in the early stage and lower in the late stage than that of late maturity varieties,which inllustrates mid-late maturity varieties were quicklyin launch of grain-filling and had short time of grain-falling period and more dry matter accumulation.[Conclusion] In order to ensure mature of maize and decrease grain water content,mid-late maturity varieties are more suitable for planting at Harbin area.%[目的]探究不同熟期玉米品种籽粒乳线比例与含水率、粒重及激素的关系,为黑龙江省不同积温带地区选择熟期适宜的玉米品种提供理论和试验依据.[方法]试验选用熟期不同的玉米品种‘先玉335’、‘鑫鑫2号’(晚熟品种)和‘绥玉23’、‘吉单27’(中晚熟品种)为材料,测定不同熟期玉米品种籽粒的乳线比例、含水率、粒重及激素含量.[结果]与晚熟品种相比,中晚熟品种籽粒乳线下移更快,含水率下降更迅速,淀粉运输和积累更快,能够安全成熟.花后55 d时,中晚熟品种籽粒乳线比例比晚熟品种大29.37％～ 35.20％,含水率较晚熟品种低18.52％～ 19.63％.各品种内源激素含量变化趋势相似,但不同熟期品种间存在差异,与晚熟品种相比,中晚熟品种IAA、GA和CTK含量更低,说明其籽粒建成更完全.灌浆前期中晚熟品种ABA含量更高,说明其灌浆启动早,后期含量更低,则说明其灌浆时间短,干物质积累快.[结论]因此,为保证玉米正常成熟,降低含水率,哈尔滨玉米种植区更适宜种植中晚熟品种.【期刊名称】《西南农业学报》【年(卷),期】2018(031)003【总页数】7页(P437-443)【关键词】熟期;乳线;含水率;粒重;激素【作者】周颖;顾万荣;张立国;李晶;刘晓双;左师宇;曹鑫波;孙继;魏湜【作者单位】东北农业大学农学院,黑龙江哈尔滨150030;东北农业大学农学院,黑龙江哈尔滨150030;黑龙江省农业科学院玉米研究所,黑龙江哈尔滨150086;东北农业大学农学院,黑龙江哈尔滨150030;东北农业大学农学院,黑龙江哈尔滨150030;东北农业大学农学院,黑龙江哈尔滨150030;东北农业大学农学院,黑龙江哈尔滨150030;安徽隆平高科种业有限公司,安徽合肥230000;东北农业大学农学院,黑龙江哈尔滨150030【正文语种】中文【中图分类】S513【研究意义】玉米授粉后，籽粒内的淀粉含量逐渐增加，会在顶部沉积成固体淀粉层，从而出现一条固乳交界线，即为乳线[1]。

玉米田间调查项目及标准1玉米调查项目及标准1.1田间调查项目及标准1.1.1播种期：播种当天的日期。

1.1.2出苗期：幼苗出土3厘米左右的穴数达到全区2/3的日期。

1.1.3幼苗长势：幼苗3—4叶时，目测幼苗长势的强弱，分强、中、弱三级记载。

1.1.4芽鞘颜色：展开2叶之前，第一叶鞘出现时的颜色，分为绿、浅紫、紫、深紫、黑紫。

1.1.5散粉期：小区60%的植株雄穗主轴上部1/3处散粉的日期。

1.1.6抽丝期：小区60%的植株雌穗抽花丝露出雌穗苞叶5厘米的日期。

1.1.7花丝颜色：新鲜花丝长出约5厘米时的颜色，分为绿、浅紫、紫、深紫、黑紫。

1.1.8成熟期：全小区90%以上果穗中部的籽粒乳线消失，籽粒基部出现黑色层，并呈现出品种固有颜色和色泽的日期。

1.1.9生育日数：统计从出苗期到成熟期的总日数。

1.1. 10活动积温：统计从出苗期到成熟期≥10℃的积温。

1.1. 11植株整齐度：开花后期目测全区植株生长的整齐程度，以整齐、中等、不整齐3级表示。

1.1. 12株高：乳熟末期，实测5株有代表性植株自地表至雄蓼顶端的平均高度，以厘米表示。

1.1. 13穗位高：测定株高的同时，实测上述五株自地表至上部穗位着生节的平均高度，以厘米表示。

1.1.14空秆率：收获时调查全区结实低于10粒的果穗的株数百分率。

1.1. 15倒伏性：目测记载倒伏日期、原因、程度、面积。

1.1. 15.1倒伏日期：记载倒伏当天的日期。

1.1. 15.2倒伏程度：分五级。

0级：植株不到。

1级：植株倾斜度不超过1 50。

2级：植株倾斜度在1 50一450之间。

3级：植株倾斜度在450一850之间。

4级：植株倾斜度超过850以上。

1.1. 15.3倒伏比例：目测，以百分率表示。

1.1. 16大斑病和灰斑病：在抽丝2 5天后目测整株的发病情况，分为五级。

1级：全株叶片无病斑或仅在穗下部叶片上有少量病斑，病斑面积少于总叶面积5%。

2级：穗上部叶片有零星病斑，穗下部叶片有少量病（占总叶面积6-10%）。

毕业论文模板/毕业论文模板：不同品种和密度对玉米生理特性及产量的影响不同品种和密度对玉米生理特性及产量的影响 杨娜，席吉龙，郝佳丽，王珂（山西省农业科学院棉花研究所，山西运城044000）摘要：在晋南小麦玉米两作区，采用裂区设计，研究拟推品种和不同密度对玉米光合速率、叶面积指数、干物质积累及产量的影响。

结果表明，随着种植密度的增加，两个品种的光合速率随密度增加而降低，叶面积指数和群体干物质积累都呈增加的趋势，而单株干物质则呈降低趋势，产量表现为先增加后降低。

正大16在任何密度下，均比大丰133显著增产，正大16和大丰133的适宜种植密度分别为82 500株/hm2和75 000株/hm2。

关键词：玉米；品种；密度；生理特性；产量0 引言玉米是我国的主要粮食作物之一，是集粮食、饲料、工业原料于一体的三元农作物[1]，玉米产量的提高源自杂种优势的应用和栽培技术的提高[2]；利用玉米新品种是最有效的增产途经，针对新品种研究适宜的栽培密度和恰当的管理措施，可更好地发挥玉米产量潜力。

前人对玉米品种密度的研究已有较多报道[3-9]。

国内外生产实践表明，玉米产量随种植密度的增加而提高，但当密度达一定程度后，产量又随密度的增加而降低[10]。

因此，研究不同品种不同密度下玉米的产量变化及生长规律，对确定适宜当地生产的合理密度具有重要意义。

本研究针对晋南小麦玉米两作区的生态条件和生产实际，以拟推品种大丰133和正大16为试研材料，分析不同密度下玉米的生理特性及产量变化规律，找到适宜本地区的高产栽培措施，为建立玉米高产栽培技术体系及大面积示范提供理论依据。

1 材料与方法1.1 试验概况试验于2016年6月至10月在山西省农业科学院棉花研究所牛家凹农场进行。

试验地前茬为小麦，播前土壤有机质12.14g/kg，全氮0.95g/kg，速效磷15.4mg/kg，速效钾181mg/kg。

播前施尿素450kg/hm2，重过磷酸钙326kg/hm2。

玉米容重标准
玉米容重是指单位体积的玉米籽粒的重量，通常以千粒重来表示。

玉米容重标准是衡量玉米品质的重要指标之一，对于玉米的种植、加工和贮藏都具有重要的意义。

下面将详细介绍玉米容重标准的相关内容。

首先，玉米容重标准的制定是为了保证玉米的品质和产量。

根据国家相关标准规定，玉米容重一般在720g/L以上为合格，低于这个数值则被认为是劣质玉米。

因此，种植玉米时要选择优质种子，并在生长期间进行科学的管理，以保证玉米容重达到标准要求。

其次，玉米容重标准与玉米的加工和贮藏密切相关。

在玉米加工过程中，玉米容重的高低直接影响到玉米加工后的产品质量，如玉米粉、玉米淀粉等。

同时，玉米容重也是衡量玉米贮藏品质的重要指标之一，高容重的玉米更容易贮藏，保鲜期更长。

另外，玉米容重标准还与玉米的销售和市场价格息息相关。

一般来说，高容重的玉米更受市场欢迎，价格也更高。

因此，种植户在选择玉米种子时，就要考虑到玉米容重标准，以获取更好的经济效益。

总的来说，玉米容重标准对于玉米的种植、加工、贮藏和销售都具有重要的意义。

种植户在种植玉米时要选择优质种子，并科学管理，以保证玉米容重达到标准要求；加工企业在生产过程中要注重玉米容重对产品质量的影响；贮藏和销售环节也要根据玉米容重标准来进行操作，以确保玉米的品质和市场竞争力。

综上所述，玉米容重标准是玉米产业中不可或缺的重要指标，对于保障玉米品质、提高经济效益具有重要意义。

希望种植户、加工企业和贸易商能够加强对玉米容重标准的认识，共同推动玉米产业的健康发展。

对玉米容重参数的认识玉米容重是衡量玉米质量的一个关键指标。

从定义上玉米容重就是指玉米籽粒单位容积内的质量，在我国其单位为g/L。

玉米容重从某种程度上能真实地反映出玉米的完整度、均匀度、成熟度以及其潜在的营养价值。

一般情况下，同一品种玉米的容重值越高，其籽粒中所含的营养物质越多。

下文将综述玉米容重差异的可能形成机制，重点分析玉米容重参数可能蕴藏的饲用营养价值，以期为正确认识玉米容重参数提供参考。

一、玉米容重差异形成机制分析1.1测定方法对玉米容重测定值的影响研究表明，采取不同取样方法测定的相同玉米的容重值可相差9g/L(张霞，2005)。

所以在测定玉米容重时须按照四分法逐量取样才能保证测定值误差在允许范围之内。

具体操作时如发现插片不流畅及受到阻力或震动等都会影响容重的测定结果。

另外将排气砣置于插板下对容重的测定比排气砣置于插板上可导致容重测定值高约32g/ L(张霞，2005;高清海和吕宏，2011)。

实际上，我国1999年发布的玉米容重测定方法测定的容重值比美国相应方法的测定值高出约30 g/L。

所以在2009年我国发布了新的玉米容重测定方法。

经验证，修订后的容重测定方法(GB1353-2009)测定结果与国外方法测定值相差不超过2.5g/L。

(即将实施的新标准是 GB1353-2018)1.2 玉米品种(质地)与容重的关系张丽(2008)分析了29 个山东省玉米品种容重的差异，发现玉米容重受到基因型的显著影响。

受基因型控制的粒型是决定容重的重要因素，不同粒型之间容重差异显著，爆裂型玉米容重值高于硬粒型，硬粒型玉米容重普遍高于马齿型玉米的容重。

这可能是因为圆形爆裂型玉米在容量筒内排列间隙小于扁平形籽粒，且圆形籽粒种皮光滑，故圆形籽粒比扁平形籽粒容重高。

同时发现容重与角质率呈极显著正相关，爆裂型玉米基本全部角质化，硬粒型的角质率大于马齿型。

这也是为什么近年来黑龙江大量种植的胶质德美亚玉米的容重普遍高于普通东北玉米的原因。

DOI：10.19462/ki.zgzy.20231101002黑龙江西部玉米产量预估模型的建立薛　瑶1　吕东辉2　叶倩竹3　刘兴丽4（1黑龙江省齐齐哈尔市气象局，齐齐哈尔161000；2黑龙江省甘南县气象局，甘南162100；3广东海洋大学，湛江524000；4黑龙江气象数据中心，哈尔滨150000）摘要：目前黑龙江西部富裕县玉米的主栽品种吉单66多年来表现较好，为进一步探索气象因子对其产量及产量构成因子的影响，以期研究出玉米产量预估模型并应用于实际生产，以玉米品种吉单66为研究对象，采用相关性分析方法，对其生育期内气象因子及玉米产量构成因子进行分析。

研究结果表明，玉米有效穗数、行粒数和百粒重与产量相关性很强；从相关性分析和线性回归分析可以看出，6月平均气温、日照时数、降水量和8月平均气温、9月降水量对玉米吉单66产量影响大，相关性强，其中9月降水量与产量呈显著负相关，其他4个气象因子为正相关；利用多元线性回归分析，建立了2种玉米产量预估模型。

经过对比分析，2种产量预估模型均比较精准，适用于吉单66玉米品种及其他黑龙江西部玉米品种产量预估，为今后黑龙江其他地区产量预估模型的建立及农业气象服务奠定了基础。

关键词：黑龙江西部；玉米；产量预估模型；气象因子；产量构成因子；相关性分析Establishment of Maize Yield Prediction Model inWestern Heilongjiang ProvinceXUE Yao1，LYU Donghui2，YE Qianzhu3，LIU Xingli4（1Qiqihar Meteorological Bureau，Qiqihar 161000，Heilongjiang；2Gannan County Meteorological Bureau，Gannan 162100，Heilongjiang；3Guangdong Ocean University，Zhanjiang 524000，Guangdong；4Heilongjang Meteorological Date Center，Harbin 150000）全球气候变暖导致气候事件呈现多发、频发、广发趋势，对人类生活、经济社会发展和农业生产等方面造成影响[1]。

2018年31卷3期 Vol. 31 No. 3西岛表业学板Southwest China Journal of A gricultural Sciences437文章编号：l〇〇l-4829(2018)3-0437-07D O I：10. 16213/j. c n k i. s c ja s.2018. 3.002不同熟期春玉米籽粒乳线比例与含水率、粒重及激素的关系周颖\顾万荣^，张立国2,李晶\刘晓双\左师宇\曹鑫波\孙继3,魏漫1(1.东北农业大学农学院,黑龙江哈尔滨150030;2.黑龙江省农业科学院玉米研究所,黑龙江哈尔滨150086;3.安徽隆平高科种业有限公司，安徽合肥230000)摘要：【目的】探究不同熟期玉米品种籽粒乳线比例与含水率、粒重及激素的关系，为黑龙江省不同积温带地区选择熟期适宜的玉米品种提供理论和试验依据。

【方法】试验选用熟期不同的玉米品种‘先玉335 ’、‘鑫鑫2号’（晚熟品种）和‘绥玉23 ’、‘吉单 27’（中晚熟品种）为材料，测定不同熟期玉米品种籽粒的乳线比例、含水率、粒重及激素含量。

【结果】与晚熟品种相比，中晚熟品 种籽粒乳线下移更快，含水率下降更迅速，淀粉运输和积累更快，能够安全成熟。

花后55 d时，中晚熟品种籽粒乳线比例比晚熟品 种大29. 37 %〜35. 20 %,含水率较晚熟品种低18. 52 %〜19. 63 %。

各品种内源激素含量变化趋势相似，但不同熟期品种间存在差异，与晚熟品种相比，中晚熟品种IA A、G A和C T K含量更低，说明其籽粒建成更完全。

灌浆前期中晚熟品种A B A含量更高，说 明其灌浆启动早，后期含量更低，则说明其灌浆时间短，干物质积累快。

【结论】因此，为保证玉米正常成熟，降低含水率，哈尔滨玉 米种植区更适宜种植中晚熟品种。

关键词：熟期；乳线；含水率；粒重；激素中图分类号:S513 文献标识码:ARelationship of Grain Milk Line Percentage of Spring Maize with ItsWater Content, Grain Weight and Hormone in Different MaturitiesZHO U Y in g1, GU W an-rong1 * , Z H A N G Li-guo2, L I Jing1, L IU Xiao-shuang1, ZUO S hi-yu1, CAO X in-b o1, SUN Ji3, W E I S hi1*(1. College of Agronomy, Northeast A gricultural U niversity, H eilongjiang H arbin 150030, C h in a；2. Maize Research In s titu te, H eilongjiangAcademy of A gricultural Sciences, H eilongjiang H arbin 150086, C h in a；3. A n h ui Longping High-tech Seed Industry Co. , L td, A n h ui Hefei 230000, C hina)A b stract:【O bjective 】A fie ld experiment was conducted to illustrate the relationship of m ilk line percentage w ith water content, grain weightand hormone of spring maize to provide a scientific and experimental inform ation for the spring maize m aturity selection of different accumula­ted temperature zone in H eilongjiang p r o v in c e.【M ethod】‘ Xianyu335 ’ and ‘ X in x in2’（ late m aturity varieties) , ‘S u iy u’ and ‘ Jidan27 ’ ^m id-late m aturity varieties) w hich had different m aturities were used as experiment m aterials, and th e ir m ilk line percentage, water con­tent ,grain weight and hormones were d e te rm in e d.【R esult】 Compared w ith late m aturity varieties, m id-late m aturity varieties could safety rip e n, grain m ilk line formed faster,w ater content declined more q u ic k ly, and the transportation and accumulation of starch were more q uick­ly. A t 55 days after anthesis, the m ilk line percentage of m id-late m aturity varieties was 29. 37 % - 35. 20 % bigger than that of late m aturi­ty varieties, and water content was 18. 52 % - 19. 63 % lower than that of late m aturity varieties. Changes of hormones were sim ilar in varie­ties but differed in diferent m aturity varieties, compared w ith late m aturity varieties, I A A, G A, C TK contents were lower in m id-late m aturity varieties, and grains were more mature. A B A content o f m id-late m aturity varieties was higher in the early stage and lower in the late stage than that of late m aturity varieties, w hich inllustrates m id-late m aturity varieties were q uic k ly in launch of g ra in-fillin g and had short time ofg ra in-fillin g period and more dry matter a c c u m u la tio n.【Conclusion 】In order to ensure mature of maize and decrease grain water content,收稿日期=2017 -03-10基金项目：国家重点研发计划“东北春玉米产量与效率层次差异形成机制与丰产增效途径”（2016Y F D0300103);哈尔滨市应用技术研究与开发项目（2015R Q Q X J046);黑龙江省博士后科研启动金项目（L B H-Q l6〇3l);黑龙江省青年科学基金(Q C2015032);东北农业大学“学术骨干”项目作者简介:周颖（1995 -)，女，黑龙江佳木斯人，硕士研究生，主要从事玉米高产栽培技术研究。

玉米灌浆后期百粒重变化的品种间差异分析
金益;张永林
【期刊名称】《东北农业大学学报》
【年(卷),期】1998(029)001
【摘要】采用回归异质性测验法分析了黑龙江省８个玉米杂交种抽丝后３０～６０ｄ期间百粒重的变化，结果表明，此期间早熟和晚熟杂交种百粒重变化的回归系数差异显著，因而平均灌浆速率也有显著差异。

【总页数】4页(P7-10)
【作者】金益;张永林
【作者单位】东北农业大学;东北农业大学
【正文语种】中文
【中图分类】S513.01
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夏玉米乳线位置与粒重及机械化收获关系的研究孟彦;孙喜云;孟凡玉;卢广远;侯倩倩【摘要】To investigate the relationship of milk line position with grain weight and mechanized harvest of summer corn in Huang-Huai-Hai Region, 8 varieties (A, B, C, D, E, F, G, H) with large planting areas were selected to measure the grain filling rate, 100-grain weight, water content and milk line position, and the correlation was analyzed. Results showed that when the milk line position was 90%, the grain filling of all the 8 varieties finished and 100-grain weight reached the highest value,which was 43.02 g. The grain filling time was in positive correlation with 100-grain weight. However, when the milk line position completely disappeared, the 100-grain weight was reduced by 8.66% at most. There was no significant difference during the periods of grain weight rising, but in the periods of grain weight falling, the traits of D, E, H were significantly different with the other varieties, and water loss rate of C and A showed significant difference with the other six varieties. The water content of grain was negatively correlated with milk line position. When the milk line percentage was 90% , the grain water content was less than 30% . The key factor influencing the mechanized harvest of summer corn is harvesting time, rather than the varieties. Moreover, milk-line position of 90% is the best time for harvest; if the harvest is too late, the yield will be reduced with varying degrees.%为研究黄淮海夏玉米乳线位置与粒重及机械化收获的关系,选用推广面积较大的8个品种(A、B、C、D、E、F、G、H)作为处理,测定其灌浆速率、百粒重、含水量及乳线位置等性状,并分析其相关性.结果表明:乳线位置在90%时籽粒灌浆已经结束,百粒重出现峰值,最高为43.02 g,灌浆时间与百粒重程正相关,乳线完全消失后,百粒重最大可降低8.66%;在粒重上升期处理间差异不显著,下降期处理D、E、H与其他处理间差异达极显著水平;脱水速率处理C、A与其他6个处理间差异显著;籽粒含水量与乳线位置呈负相关,乳线下移至90%,籽粒含水量在30%以下.影响夏玉米机械化收获籽粒的关键因素是收获时间,而不是品种;乳线位置下移至90%是夏玉米收获的最佳时间,收获过晚产量会有不同程度的降低.【期刊名称】《农业科学与技术（英文版）》【年(卷),期】2017(018)010【总页数】5页(P1841-1844,1851)【关键词】玉米;灌浆速率;百粒重;乳线位置;机械化收获【作者】孟彦;孙喜云;孟凡玉;卢广远;侯倩倩【作者单位】商丘市农林科学院,河南商丘 476000;商丘市农林科学院,河南商丘476000;商丘市农林科学院,河南商丘 476000;商丘市农林科学院,河南商丘476000;商丘市农林科学院,河南商丘 476000【正文语种】中文T he summer corn planting area in Huang-Huai-Hai is one of the three major corn planting dominant areas in China.Because of the influences of climate,farming system,planting habit,production cost and mechanization development level,the planting efficiency of corn is low.The fundamental way to improve the planting benefits of corn is to realize the fullmechanization of summer corn production.The formation of maize grain yield is mainly determined by the grain filling rate and filling duration,also affected by environmental conditions[1-4],and the corn grain filling duration is in linear correlation with 100-grain weight and yield.Since grain water content is the key factor affecting the corn quality and mechanized harvest during the harvesting[5],it can get the highest dry matter yield from the 2/3 of milk line stage to the appearance of black aleuronelayer[6-7],when the harvested grains have high water content,bringing inconvenience to transportation and storage[8].With the extension of filling time,the 100-grain weight decreases for different varieties to different degrees until the total disappearance of milk line,which is also affected the corn quality[9-10].In order to further improve the yield and benefit of summer corn,it is the most important problem for the development of summer maize production to strengthen the study on the mechanization and high yield supporting cultivation techniques. In this study,8 representative varieties(also 8 treatments)with large planting areas in Huang-Huai-Hai Region were used as the test materials.Based on the characteristics of summer corn production in this region,the relationship between the filling time of different varieties and mechanized harvest was investigated through the study on the relationship among filling time,100-grain weight,grain water content and yield for 2 continuous years,so as to provide theoreticalreferences and technical guidance for realizing combination of summer corn high yield and mechanized cultivationtechnique,increasing corn yield,improving land output efficiency,and promoting agricultural efficiency increase.Soil conditions in the test siteThe test was conducted in the double eight test base of Shangqiu Academy of Agriculture and Forestry Sciences,Henan Province(39.9289N,116.388 3E)in 2014 and 2015 for two consecutive years,and the test site was the winter wheat-summer maize rotation land for many years.The soil was light loam soil,and the soil sampling test in 2014 in the laboratory of Shangqiu Academy of Agriculture and Forestry Sciences,Henan Province showed that the 0-20 cm soil of the plough layer had an organic matter content of 1.53%,total nitrogen(N)content of 0.082%,hydrolysable nitrogen of 40.65 mg/kg,available phosphorus (P2O5)of 69.66 mg/kg,available potassium(K2O)of 102.94 mg/kg,and water soluble calcium content of0.18%.Test designThe test corn varieties were the 8 representative varieties with large promotion and cultivation area in Huang-Huai-Hai corn planting area,in other words,there were 8 treatments.The test varieties were purchased from the seed market in Shangqiu,and test treatments were shown in Table 1.Test design:the test plot had an area of 20 m2,with the line spacing of 0.6 m,line length of 6.7 mm and row spacing of 0.222 m,and the plot had 5 lines with the planting density of 75 000 plants/hm2.There were a total of 3 repetitions,and all treatment were in randomized block design.Sowingand harvesting time:the first year seeds sowing was on June 4,2014,and there were 5 times of harvests on September 19,September 15,September 20,September 25 and September 30 accompanied with timely examination;the secondyearseeds sowing was on June 14,2015,and the 5 times of harvests were on September 15,September 20,September25,September 30 and October 5,accompanied with timely examination.Other management was the same with field production. Survey items and methodsExperimental investigation items:Grain filling rate (Gr),Rate of waterloss(Wr),harvested grain water content,100-grain weight,Milk line percentage(Mp).And the calculation formulas for Grain filling rate,Rate of water loss and Milk line percentage were as shown in thefollowingFormula(1),(2)and(3). The 100-grain weight was the average value of 3 times;the harvested grain moisture contetn was measured timely after threshing using Nongao computer moisture tester.Data statisticsExcel was used to analyze,process and map the teat data,and SAS 8.0 was used to make the multiple comparisons(LSD).Analysis of 100-grain weightAs shown in Table 2,the value of F was 0.82,which was smaller than the critical value of 2.31,indicating that the differences in 100-grain weight among all treatments reached the significant level.When the milk line position was 90%,the 100-grain weight reached the highestvalue.Treatment C had the largest 100-grain weight of 43.02 g,which was significantly different from the other treatments,followed by treatment E,treatment A,treatment D,treatment H and treatment B,which showed no significant difference between each other.The 100-grain weight was the lowest in treatment F of 35.01 g,and the difference from treatmentC,treatment E,treatment G and treatment A reached the significant level,but the difference was not significant with treatment H,treatment D and treatment B.At 5-8 before the disappearance of milk line,the 100-grain weight of all treatments reached the highest value,and with the filling time delaying,100-grain weight presented decreasing trend,which was consistent with the test results in 2014 and 2015.However,the decreases were different for different treatments,and the decreasing amount was in the order of treatment C>treatment A>treatment F>treatmentB>treatment G>treatment E>treatment D>treatment H,which was3.68,3.53,2.85,2.76,2.33,1.33,1.06 and 0.93,respectively.The results showed that the 100-grain weight was positively related to the grain filling time to a certain extent,but after reaching the peak,the 100-grain weight was negatively correlated with the grain filling time.Grain filling rateAs shown in Fig.1,can be seen from Figure 1,the filling rate varied greatly among different treatments.The test results for 2 consecutive years showed that during the grain filling stage,the 100-grain weight was divided into rise period(2014 R)and decline period (2014D).During the rise period of 100-grain weight,the grain filling rate was the highest intreatment E with the average value of 0.64 for 2 years,indicating thatthe grain weight increased fast in treatment E,followed by treatment B and treatment G,both of which had an average of 0.62 for 2 years.Treatment D had the smallest grain filling rate with the average of 0.45 for 2years,indicating that the grain weight increased slowly in treatmentD.However,the difference among all treatments was not significant.During the decline period of 100-grain weight,treatment C had an average grain filling rate of 0.75 for 2 years,which showed significant difference with the other treatments,indicating that it needed timely harvest when reaching physiological maturity,otherwise it would cause serious yield reduction;treatment B came to the second with an average grain filling rate for 2 years of 0.67.Treatment H had the smallest grain filling rate with an average of 0.16 for 2 years,and the differences with treatmentA,treatment B,treatment C,treatment F,treatment G all reached significant level.However,treatment H showed no significant difference with treatment D and treatment E,indicating that delaying harvest had no significant influence on the yield of these 3 treatment after harvest.Rate of water lossAs shown in Fig.2,there was no significant difference in water loss rate for all treatments in different years,but the difference reached significant level in water loss rate among different treatments.The average water loss rate of treatment C was the highest of 0.80,followed by treatment with an annual average water loss rate of 0.77,and the difference between the two was not significant,but the differences between the two and the other 6treatments reached the significant level.The annual average water loss rate of treatment G was 0.75,which showed no significant difference with treatment A,but the differences with the other 6 treatments reached significant level.The annual average water loss rate of treatment E was0.67,and the differences with treatment C,treatment A,treatmentG,treatment F reached significant level.However,there was no significant difference among treatment D,treatment H,treatment B and treatment F,which had the water loss rate of 0.63,0.63,0.62 and 0.61,respectively.The difference between treatmentC,treatmentA,treatmentG and the other treatments reached extremely significant level.Relationship between grain water content and milk line percentage Water content of less than 30%is the water index to achieve mechanized harvest[11].As shown in Table 3,the test results in 2015 were consistent with the results in 2014.Therefore,grain filling and water loss of corn was proceeded at the same time[12],and with the downward shift of milk line position,the grain water content became less and less,so the two were negatively correlated.On September 30,the milk line of treatment D and treatment G had disappeared completely,and the water content of the two was 25.1%,26.2%,respectively.On the other hand,at this time,the milk line in treatment A,treatment B,treatment E and treatment F shifted downward to 90%of the grain,and the grain water contentin these treatments was greater than 27.0%but all less than 30%.On September 30,all treatments had grain filling completed,and then the water content decreased rapidly.At the same time,dry matter flowed back,leading to the decrease ofgrain weight.However,when the milk line position didn’t reached 90%,most treatments had the grain water content over 30%,so none could be conducted with mechanized harvest directly.But when the milk line percentage was over 90%,all the 8 treatments had the grain water content less than 30%,which could fully carry out mechanized harvesting.Milk line position reflects maize grain filling progress,and grain filling time directly affects the 100-grain weight and water content of corn.Grain water content is in linear correlation with grain filling time[13].LIet al.[14]found that different varieties had different grain filling rate and water loss rate.On the other hand,grain water content is an decisive factor determining whether it can carry out mechanized harvesting directly.The 100-grain weight is in positive correlation with yield,while the grain filling time is in negative correlation with water content,and grain filling control is under the combined control of related gens and cultivation conditions[15].In this study,the results showed that the 100-grain weight was positively related to grain filling time in a certain range,but after reaching the peak,100-grain weight was negatively correlated with grain filling time.When the milk line percentage reached 90%,the 100-grain weight reached the peak after filling,which was inconsistent with the results of QIN et al.[16],WANGet al.[17]finding that the grain filling completed and the grain weight reached the highest at the disappearance of milk line.There was no significant difference in the grain filling rate among all treatments.And when the milk line percentage reached 90%,the grain water content decreased to 27%or so,which was the best time for mechanized harvesting.Therefore,the grainfilling time was the decisive factor determining whether the summer corn in Huang-Huai-Hai Region could adopt mechanized harvest directly or not,but was not related with the variety.With the extension of grain filling time,when the milk line position went beyond 90%,the grain water content decreased rapidly,and when the milk line disappeared completely,the decrease of 100-grain weight was the largest in treatment A of 8.665,while smallest in treatment H of 2.36%.And the differences in grain filling rate among all the treatments reached extremely significant level.The changes of water loss rate among all treatments also reached the extremely significant level,indicating that different varieties had different water loss rate,which was consistent with previous research[14].Although the 8 representative varieties with large planting area were used in thetest,limited by ecological area in test design,further research is needed to test the summer corn in other ecological areas.The breeding of variety for mechanized harvest should pay attention to observing whether the grain filling time can adapt to the local agricultural ecological conditions,and in production,it should give comprehensive consideration to the grain filling,water loss and other yield characteristics of different corn varieties[18-19].The yield of corn was the highest when the grain filling reached the milk position of 90%,when the bracts became completely yellow,and the outer bract became withered.The best time for mechanized harvest was when the grain water content reduces to 27%or so.When the milk line completely disappeared,the bracts were dry and fluffy,and the 100-grainweight and yield decreased to different degrees.Moreover,the differences among different treatments reached extremely significant level,which has not been reported before.[1]JOHNSON DR,IANINER LW.Calculation of the rate and duration of grain filling in corn (Zea mays L.)[J].Crop Science,1972,12(4):485-486.[2]WU CS(吴春胜).Studies on characteristics of grain filling and dry matter accumulation of super high-yield maize(超高产玉米灌浆速率与干物质积累特性研究)[J].Journal of Jilin Agricultural University,2008,30(4):382-385. [3]LIU WR(刘武仁),ZHENG JY(郑金玉),LUO Y (罗洋),et al.Factors affecting water content of maize and cultural practice for low water content maize(影响玉米籽粒含水量的因素及低水分玉米生产技术)[J].Journal of Jilin Agricultural Sciences,2009,34(1):1-2,33.[4]LI YJ (李艳杰).Preliminary study on correlations between maize grain water and variety characters(玉米籽粒水分与品种性状相关性研究初报)[J].Journal of Maize Sciences,2000,8(4):37-38.[5]ZHANG L(张林),ZHANG BS(张宝石),WANG X(王霞),et al.Correlation analysis of agronomic characters and grain moisture in maize harvest time(玉米收获期籽粒含水量与主要农艺性状相关分析)[J].Journal of Northeast Agricultural University,2009,40(10):9-12.[6]XUE JQ(薛吉全),MA GS(马国胜),LU HD(路海东),et al.The regulation and control of density on relationship of sinksource and yield of different maize(密度对不同类型玉米源库关系及产量的调控)[J].Acta Botanica Boreali-Occidentalia Sinica,2001,21(6):1162-1168.[7]WU JY(吴建宇),XU CL(徐翠莲),REN HP (任和平),et al.Study on the qualityin different harvesting dates of corn (玉米不同收获期的子粒品质研究)[J].Acta Agriculturae Universitatis Henanensis,1994,28(1):92-94.[8]BRENDA LG,LUCAS B,MARA E,et al.Kernel water relations and duration ofgrain filling in maize temperate hybrids[J].Field CropsResearch,2007(101):1-9.[9]SUN HY,ZHANG XY,CHEN SY,et al.Effects of harvest and sowing time on the performance of the rotation of winter wheat-summer maize in the North china plain[J].Industrial Crops and Products,2007,25(3):239-247. [10]WANG XZ (王西芝),LI JH (李继海),BAI HL (白洪立),et al. Study on the best harvesting time of summer directly sown maize in southwest Shandong(鲁西南地区夏直播玉米最佳收获时期研究)[J].China Seed Industry,2009(7):40-41.[11]MENG FY(孟凡玉),MENG Y(孟彦),SUN J(孙剑),et al.Mechanized harvesting technology of summer maize(夏玉米机械化收获技术)[J].China Seed Industry,2014(10):77-77.[12]WEI YQ (卫勇强),LEI XB (雷晓兵),LIANG XW(梁晓伟).Study on the natural grain dehydration rate of different summer maize varieties(不同夏玉米品种籽粒自然脱水速率的研究)[J].Jiangsu Agricultural Sciences,2011,39(6):167-168.[13]HADI G.Effect of the length of the kernel filling period and the kernel filling rate on the grain yield of maize under different water supply conditions[J].Cereal Res Commun,2004(32):465-470.[14]LI DX (李德新),GONG XJ(宫秀杰),QIAN CR (钱春荣).Difference and correlation analysis of grain milking Rate and grain dehydrating rate on maize(玉米籽粒灌浆及脱水速率品种差异与相关分析)[J].Chinese Agricultural Science Bulletin,2011,27(27):92-97.[15]LIU ZH(刘宗华),ZHANG ZH(张战辉).Research progress on grain filling rate in maize(玉米籽粒灌浆速率研究进展)[J].Journal of Northeast Agricultural University,2010,41(11):148-153.[16]QIN YY(秦营营),DONG ST(董树亭).Relationship among kernel milk line formation,water content,grain weight and nutrients accumulation of summer maize(夏玉米子粒乳线比例与含水量、粒重及营养物质积累的关系)[J].Journal of Maize Science,2014,22(2):81-86.[17]WANG ZX(王忠孝),DU CG(杜成贵),WANG QC (王庆成).Study on the symbol of maize mature-milk line(玉米籽粒成熟标志一乳线的研究)[J].Shandong AgriculturalSciences,1986(4):36,47.[18]FENG P(冯鹏),SHEN XH(申晓慧),ZHENG HY (郑海燕),et al.Effects of planting density on kernel filling and dehydration characteristics for maize hybrids(种植密度对玉米籽粒灌浆及脱水特性的影响)[J].Chinese Agricultural Science Bulletin,2014,30(6):92-100.[19]LI SC (李绍长),LU JH (陆嘉惠),MENG BM (孟宝民),et al.The relationship between endosperm cell differentiating and grain filling (玉米籽粒胚乳细胞增殖与库容充实的关系)[J].Journal of Maize Sciences,2008,8(4):45-47.。

玉米粒密度
玉米粒，那小小的一颗颗，可别小瞧了它们！你知道玉米粒的密度有多大魔力吗？
想想看，每一颗玉米粒都像是一个小小的宇宙，蕴含着无尽的奥秘。

它们紧密地排列在一起，就像一群小伙伴挤在一起取暖。

玉米粒的密度啊，决定了它们在袋子里能装多少，在仓库里能堆多高。

这可不是一件简单的事儿呢！就好像盖房子，你得考虑用多少砖头才能既坚固又不浪费。

玉米粒也是一样呀，密度合适了，才能发挥出最大的作用。

你有没有试过抓一把玉米粒在手里？那种感觉，实实在在的，能让你真切地感受到它们的存在。

它们可不是虚无缥缈的东西，而是有着自己独特性质的宝贝呢！如果玉米粒的密度太小，那一把抓起来是不是就感觉轻飘飘的，没什么分量？但要是密度太大呢，又好像过于沉重，拿起来都费劲。

我们的生活中不也有很多类似的情况吗？就像交朋友，朋友之间的关系也有个密度问题呢。

太疏远了不行，太紧密了也会让人透不过气来。

玉米粒的密度就像是一种平衡，一种恰到好处的状态。

再看看那些农民伯伯们，他们在田地里辛勤劳作，不就是为了收获那一颗颗饱满的玉米粒吗？而玉米粒的密度，不正是他们努力的成果体现之一吗？这难道不值得我们去重视，去好好研究一番吗？
玉米粒的密度，看似普通平凡，却蕴含着如此多的道理和趣味。

它让我们明白，即使是最微小的事物，也有着不可忽视的价值和意义。

我们不能因为它小就忽略它，而应该用心去感受，去发现它的独特之处。

所以啊，别再小看玉米粒的密度啦，它可是有着大文章呢！。